<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>
  </head>

  <body>
    <div id="app">
      <button @click="fullName='li xiaoxiao'">change</button>
      <h2>全名是{{fullName}}</h2>
    </div>
    <script>
      Vue.config.productionTip = false;

      const vm = new Vue({
        el: "#app",
        data() {
          return {
            firstName: "Wang",
            lastName: "zhongwang",
          };
        },
        //computed配置项,内部专门用来书写计算属性
        computed: {
          //以下书写方式就是代表当前计算属性是只读的
          // fullName() {},

          //计算属性可读可写(当获取fullName的值的时候就调用getter函数,当对fullName进行设置的时候,会调用setter函数)
          fullName: {
            get() {
              console.log("getter");
              return (
                this.firstName.toLowerCase() + " " + this.lastName.toLowerCase()
              );
            },
            set(val) {
              /* set函数中的参数就是计算属性被设置的值 */
              console.log("setter", val);

              //setter中的逻辑我们可以自由发挥
              this.firstName = val.split(" ")[0];
              this.lastName = val.split(" ")[1];
            },
          },
        },
      });
    </script>
  </body>
</html>
